Parametrization of quark and gluon generalized parton distributions in a dynamical framework

Journal Article · Tue Mar 29 00:00:00 EDT 2022 · Physical Review D

DOI:https://doi.org/10.1103/PhysRevD.105.056022· OSTI ID:1859822

Kriesten, Brandon; Velie, Philip; Yeats, Emma; Lopez, Fernanda Yepez; Liuti, Simonetta

We present a parametrization of the chiral even generalized parton distributions, $$H, E, \tilde{H}, \tilde{E}$$, for the quark, antiquark, and gluon, in the perturbative QCD (pQCD)-parton framework. Parametric analytic forms are given as a function of two equivalent sets of variables $x, ξ, t$ (symmetric frame) and $X, ζ, t$ (asymmetric frame), at an initial scale, $$Q^2_o$$. In the X > ζ region, a convenient and flexible form is obtained as the product of a Regge term ∝ X$$^{-a+a't}$$, describing the low X behavior, times a spectator model-based functional form depending on various mass parameters; the behavior at X < ζ is determined using the generalized parton distributions symmetry and polynomiality properties. The parameters are constrained using data on the flavor separated nucleon electromagnetic elastic form factors, the axial and pseudoscalar nucleon form factors, and the parton distribution functions from both the deep inelastic unpolarized and polarized nucleon structure functions. For the gluon distributions we use, in particular, constraints provided by recent lattice QCD moments calculations. The parametrization’s kinematical range of validity is o.ooo1 ≤ X ≤ 0.85, 0.01 ≤ ζ ≤ 0.85, 0 ≤ -t ≤ 1 Gev², 2 ≤ Q² ≤ 100 GeV². With the simultaneous description of the quark, antiquark, and gluon sectors, this parametrization represents a first tool enabling a global QCD analysis of deeply virtual exclusive experiments.

• Research Organization: Univ. of Virginia, Charlottesville, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC); Southeastern Universities Research Association (SURA)
• Grant/Contract Number: SC0016286; C2019-FEMT-002-04; C2020-FEMT-006-05
• OSTI ID: 1859822
• Alternate ID(s): OSTI ID: 1980047
• Journal Information: Physical Review D, Journal Name: Physical Review D Vol. 105 Journal Issue: 5; ISSN 2470-0010
• Publisher: American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
Electron-ion collisions
QCD in nuclear reactions
gluons
Hadrons
angular momentum
spin